Review OCZ Vertex 450 256 GB

These days the 6 Gbps SATA interface imposes a cap on the sequential transfer speeds of modern SSDs. To go higher you have to use RAID or PCI Express. In the AS SSD benchmark, which is a versatile and useful test but has quite large error bars, our Vertex 450 comes in at 506 MB/s in the sequential read test – more or less within the margin of error compared to the other high-end drives. 

Sequential write speeds are also impressive at 492 MB/s. With Crystal Disk Mark, the drive’s sequential read speeds were a bit lower at 468 MB/s and write speeds 489 MB/s. In HD Tune, the result is on par with the Vector and Vertex 4, i.e. a bit behind the competition.

In the chart on the right it is easier to visualize the Vertex 450's performance versus the Vector under (unrealistically) ideal circumstances. It's easy to see that the two drives use the same controller, with the Vertex 450 being marginally slower than its predecessor. 

Performance drops over time is problem that affects all SSDs. Modern SSD controllers handle these drops with the help of wear leveling, garbage collection and other complex processes, and they do so with varying degrees of success. 

The problem is compounded as the drive starts to fill up, as there will be less spare area on which to distribute the subsequent writes and erases. Large-capacity drives or drives with much over-provisioning have an advantage here as the extra spare area reduces write amplification.

To see how well an SSD handles these issues we put the drive though a stress test using the "IOMix" profile in IOMeter. Data is written and read repeatedly to the entire drive for 60 minutes. The performance was tested before and after the torture test with AS SSD. Unlike drives with over-provisioning, the write speeds of the Vertex 450 drop significantly right after the test. 4K reads and writes are largely unaffected. 

During daily use, the rather boring reality is that most of the time you are unlikely to notice any difference between any of the current high-end SSDs. Windows startup is one such occasion, where all SSDs are much faster than conventional drives, but with little difference between individual models. Not counting POST, you should be able to reach the Windows 8 desktop in less than 10 seconds. 

It is similarly hard to distinguish the different SSDs when starting applications and games, whereas the difference is very noticeable when comparing to an older hard drive. The Toshiba MK6461GSYN 640 GB 7200 rpm notebook hard drive needs 72 seconds to start the single-player campaign in Battlefield 3, while the same task takes 19-20 seconds with any modern SSD, and not much more than that with an older SSD.

Differences will however start to show in lengthier and more specific file copy tests.  In AS SSD's  built-in copy benchmark, the Vertex 450 cannot quite keep up with the Vector or the 840 Pro in the "ISO" test, but ends up surprisingly far ahead of them in the "Game" test. These results vary a great deal, but the high game copy result was repeatable.